Potassium 4-methyl-1,2,4-oxadiazolidine-3,5-dione and sodium 4-methyl-1,2,4-oxadiazolidine-3,5-dione

ABSTRACT

This invention discloses the compound 2-(2,4dichlorophenoxyacetyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione and its use as a herbicide. Further disclosed are the compounds potassium 4-methyl-1,2,4-oxadiazolidine-3,5-dione and sodium 4methyl-1,2,4-oxadiazolidine-3,5-dione.

United States Patent Krenzer [151 3,671,538 (451 June 20,1972

[54] POTASSIUM 4-METHYL-l,2,4-

OXADIAZOLIDlNE-3,5-DIONE AND SODIUM 4-METHYL-1,2,4-OXADIAZOLIDINE-3,5-DIONE [72] inventor: John Krenzer, Oak Park, Ill.

[73] Assignee: Velsicol Chemical Corporation, Chicago,

ill.

[22] Filed: Aug. '14, 1970 [21] Appl. No.: 63,945

Related US. Application Data [62] Division of Ser. No. 853,945. Aug. 28,1969, Pat. No.

[52] US. Cl ..260/307 B [5 l Int. Cl. ..C07d 85/52 Assistant Examiner-R.V. Rush Attorney-Robert .l. Schwarz ABSTRACT This invention disclosesthe compound 2-(2,4- dichlorophenoxyacetyl )-4-methyl-l,2,4-oxadiazolidine-3,5- dione and its use as a herbicide. Furtherdisclosed are the compounds potassium 4-methyl-l,2,4-oxadiazolidine-3,5-dione and sodium 4-methyll ,2,4-oxadiazolidine-3 S-dione.

3 Claims, No Drawings POTASSIUM 4-METHYL- l ,2,4-OXADIAZOLlDlNE-3 .5-DIONE AND SODIUM 4-METHYL-l ,2,4- XADlAZOLIDlNE-3,5-DIONE Thisapplication is a divisional application of my copending application Ser.No. 853,945, filed Aug. 28, [969, now U.S.

and can be prepared by reacting 2,4-dichlorophenoxyacetyl chloride withan intermediate compound of this invention having the structural formulawherein M is potassium or sodium.

This reaction can be effected by combining the reactants in an inertorganic reaction medium such as acetone and heating the mixture for aperiod of several hours. After this time the reaction mixture can befiltered to remove the potassium chloride that has formed and can bestripped of solvent to obtain the desired product.

The intermediate compouns of Formula I] of this invention can beprepared from the known compound N-hydroxy-O- ethylcarbamate (Journal ofOrganic Chemistry, 24, 431, 1959) by reaction with methyl isocyanate andthereafter treating with potassium or sodium hydroxide. This reactioncan be effected by slowly adding the isocyanate to a solution of thecarbamate in a suitable solvent such as diethylether and in the presenceof a small quantity of dibutyltin diacetate catalyst and thereaftertreating the resulting product, which can be recovered upon evaporationof the solvent and excess isocyanate, with an alcoholic solution of thepotassium or sodium hydroxide. The desired product forms as aprecipitate and can be recovered by conventional means.

The preparation of the compounds of the present invention is morespecifically illustrated in the following examples.

EXAMPLE 1 Preparation of Potassium 4-Methyl-1,2,4-oxadiazolidine-3,5-dione N-Hydroxy-O-ethylcarbamate (240 grams), diethyl-ether I00 ml)and dibutyltin diacetate (2 drops) were charged into a glass reactionvessel equipped with a mechanical stirrer and reflux condenser. Methylisocyanate (150 ml; 2.54 mol) was then added, with stirring over aperiod of about 1 hour. After this time the reaction mixture wassubjected to distillation to remove the solvent and excess isocyanatefrom the reaction product which had formed. Part of the product (81grams) was then added to a solution of potassium hydroxide (32.5 grams;87 percent) in methanol (400 ml) at 25 C resulting in the formation of aprecipitate. This precipitate was recovered by filtration and wasrecrystallized from methanol to yield the desired product potassium4-methyl-l ,2,4oxadiazolidine-3,5- dione having the following elementalanalysis as calculated for C H KNO C H N Theoretical 23.38 L96 l8. l 8Found 22.82 1.89 l7.94

EXAMPLE 2 Preparation of 2-(2,4Dichlorophenoxyacetyl)-4-methyll,2,4-oxadiazolidine-3,5-dione 2,4-Dichlorophenoxyacetyl chloride (9.2grams), potassium 4-methyl-l,2,4-oxadiazolidine-3,S-dione (6 grams) andacetone were charged into a glass reaction vessel equipped with amechanical stirrer. The reaction mixture was stirred for a period ofabout four hours at room temperature. After this time the reactionmixture was filtered to remove the potassium chloride which had formed.The filtrate was then stripped of solvent under reduced pressure toyield a solid residue. The residue was recrystallized from n-propanol toyield the desired product 2-(2,4-dichlorophenoxyacetyl)-4-methyll,2,4-oxadiazolidine-3,5-dione having a melting point of 138 to 139 C andhaving the following elemental analysis as calculated for C H Cl N O C HN Theoretical 41.44 2.53 8.78 Found 40.77 2.57 8.57

EXAMPLE 3 Preparation of Sodium 4-Methyl-1,2,4-oxadiazolidine-3,5- dioneN-Hydroxy-O-ethylcarbamate (210 grams; 2 mol) diethylether ml) anddibutyltin diacetate (2 drops) are charged into a glass reaction vesselequipped with a mechanical stirrer and reflux condenser. Methylisocyanate ml; 2.54 mol) is then added, with stirring, over a period ofabout 1 hour. After this time the reaction mixture is subjected todistillation to remove the solvent and excess isocyanate from thereaction product which is formed. Eighty grams of this product are thenadded to a solution of sodium hydroxide (20 grams) in methanol (350 ml)at room temperature resulting in the formation of a precipitate. Thisprecipitate is recovered by filtration and is recrystallized to yieldthe desired product sodium 4-methyll ,2,4-oxadiazolidine-3,5-dione.

EXAMPLE 4 Preparation of 2-(2,4-Dichlorophenoxyacetyl)-4-methyl-1,2,4-oxadiazolidine-3 ,S-dione 2,4-Dichlorophenoxyacetyl chloride (24grams; 0.1 mol), sodium 4-methyl-l,2,4-oxadiazolidine-3,S-dione (14.8grams; 0.1 mol) and acetone are charged into a glass reaction vesselequipped with a mechanical stirrer. The reaction mixture is stirred fora period of about 4 hours and is then filtered to remove the sodiumchloride that is formed. The filtrate is then stripped of solvent underreduced pressure to yield the desired product2-(2,4-dichlorophenoxyacetyl)-4-methyll ,2,4-oxadiazolidine-3,5-dione asthe residue.

For practical use as a herbicide, the compound of this invention isgenerally incorporated into herbicidal compositions which comprise aninert carrier and a herbicidally toxic amount of the compound. Suchherbicidal compositions, which can also be called formulations, enablethe active compound to be applied conveniently to the site of the weedinfestation in any desired quantity. These compositions can be solidssuch as dusts, granules or wettable powders; or they can be liquids suchas solutions, aerosols or emulsifiable concentrates.

For example, dusts can be prepared by grinding and blending the activecompound with a solid inert carrier such as the tales, clays, silicas,pyrophyllite, and the like. Granular formulations can be prepared byimpregnating the compound, usually dissolved in a suitable solvent, ontoand into granulated carriers such as the attapulgites or thevermiculites, usually of a particle size range of from about 0.3 to 1.5mm. Wettable powders, which .can be dispersed in water or oil to anydesired concentration of the active compound, can be prepared byincorporating wetting agents into concentrated dust compositions.

The active compound is sufficiently soluble in common organic solventssuch as kerosene or xylene so that it can be used directly as solutionsin these solvents. Frequently, solutions of herbicides can bedispersedunder superatmospheric pressure as aerosols. However, preferred liquidherbicidal composi tions are emulsifiable concentrates, which comprisethe active compound according to this invention and as the inertcarrier, a solvent and an emulsifier. Such emulsifiable concentrates canbe extended with water and/or oil to any desired concentration of activecompound for application as sprays to the site of the weed infestation.The emulsifiers most commonly used in these concentrates are nonionic ormixtures of nonionic with anionic surface-active agents; With the use ofsome emulsifier systems an inverted emulsion (water in oil) can beprepared for direct application to weed infestations.

A typical herbicidal composition according to this invention isillustrated by the following example, in which the quantities are inparts by weight.

Product of Example 2 Powdered Tale The above ingredients are mixed in amechanical grinderblender and ground until a homogeneous, free-flowingdust of the desired particle size is obtained. This dust is suitable fordirect application to the site of the weed infestation.

The compound of this invention can be applied as a herbicide in anymanner recognized by the art. One method for the control of weedscomprises contacting the locus of said weeds with a herbicidalcomposition comprising an inert carrier and, as an essential activeingredient, in a quantity which is herbicidally toxic to said weeds, thecompound of the present invention. The concentration of the new compoundof this invention in the herbicidal compositions will vary greatly withthe type of formulation and the purpose for which it is designed, butgenerally the herbicidal compositions will comprise from about 0.05 toabout 95 percent by weight of the active compound of this invention. Ina preferred embodiment of this invention, the herbicidal compositionswill comprise from about 5 to about 75 percent by weight of the activecompound. The compositions can also comprise such additional substancesas other pesticides, such as insecticides, nematocides, fungicides, andthelike; stabilizers, spreaders, deactivators, adhesives, stickers,fertilizers, activators, synergists, and the like.

The compound of the present invention is'also useful when combined withother herbicides and/or defoliants, dessicants, growth inhibitors, andthe like in the herbicidal compositions heretofore described. Theseother materials can comprise from about 5 percent to about 95 percent ofthe active ingredients in the herbicidal compositions. Use ofcombinations of these other herbicides and/or defoliants, dessicants,etc., with the compound of the present invention provide herbicidalcompositions which are more effective in controlling weeds and oftenprovide results unattainable with separate compositions of theindividual herbicides. The other herbicides, defoliants, dessicants andplant growth inhibitors, with which the compound of this invention canbe used in the herbicidal compositions to control weeds, can includechlorophenoxy herbicides such as 2,4-D, 2,4,5-T, MCPA, MCPB, 4(2,4-DB),2,4-DEB, 4-CPB, 4-CPA, 4CPP, 2,4,5-TB, 2,4,5-TES, 3,4-DA, silvex, andthe like; carbamate herbicides such as lPC, CIPC, swep, barban, BCPC,CEPC, CPPC,and the like; thiocarbamate and dithiocarbamate herbicidessuch as CDEC, metham sodium, EPTC, diallate, PEBC, perbulate, vernolate,and the like; substituted urea herbicides such as norea, siduron,dichloral urea, chloroxuron, cycluron, fenuron, monuron, monuron TCA,diuron, linuron, monolinuron, neburon, buturon, trimeturon, and thelike; symmetrical triazine herbicides such as simazine, chlorazine,atretone, desmetryne, norazine, ipazine, prometryn, atrazine,trietazine,

simetone, prometone, propazine, ametryne, and the like; chloroacetamideherbicides such as alpha-chloro-N,N-

dimethylacetamide, CDEA, CDAA, alpha-chloro-N- isopropylacetamide,2-chloro-N-isopropylacetanilide, 4- (chloroacetyl )morpholine, 1-(chloroacetyl )piperidine, and

the like; chlorinated aliphatic acid herbicides such as TCA, dalapon,2,3-dichloropropionic acid, 2,2,3-TPA, and the like; chlorinated benzoicacid and phenylacetic acid herbicides such as 2,3,6-TBA, 2,3,5,6-TBA,dicamba, tricamba, amiben fenac, PBA, 2-methoxy3,-dichlorophenylaceticacid, 3- methoxy-Z,-dichlorophenylacetic' acid, 2-methoxy-3,5,6trichlorophenylacetic acid, 2,4-dichloro-3-nitrobenzoic acid, and thelike; and such compounds as aminotriazole, maleic hydrazide, phenylmercuric acetate, endothal', biuret, technical chlordane, dimethyl2,3,5,-tetrachloroterephthalate, diquat, erbone, DNC, DNBP,dichlobenile, DPA, diphenamid, dipropalin, triflurelin, solan, dicryl,merphos, DMPA, O-S- dimethyl tetrachlorothioterephthalate, methyl2,3,5,6- tetrachloro-N-methoxy-N-methylterephthalamate, 2-[ 4-chloro-o-tolyl)-oxy]-N-methoxyacetamide, DSMA, MSMA, potassium azide,acrolein, benefin, bensulide, AMS, bromacil, bromoxynil, cacodylic acid,CMA, CPMF, cypromid, DCB, DCPA, dichlone, diphenatril, DMTT, DNAP, EBEP,EXD, HCA, ioxynil, lPX, isocil, potassium cyanate, MAA, MAMA, MCPES,MCPP, MH, molinate, NPA, OCH, paraquat, PCP, picloram, DPA, PCA,pyrichlor, sesone, terbacil, terbutol, TCBA, brominil, CP-50l44,H-l76-l, H-732, M-2901, planavin, sodium tetraborate, calcium cyanamid,DEF, ethyl xanthogen disulfide, sindone, sindone B, propanil, and thelike.

Such herbicides can also be used in the methods and compositions of thisinvention in the form of their salts, esters, amides and otherderivatives whenever applicable to the particular parent compounds.

Weeds are undesirable plants growing where they are not wanted, havingno economic value, and interfering with the production of cultivatedcrops, with the growing of omamental plants, or with the welfare oflivestock. Many types of weeds are known, including annuals such aspigweed, lambsquarters, foxtail, crabgrass, wild mustard, fieldpennycress, ryegrass, goose-grass, chickweed, wild oats, velvet leaf,purselane, barnyard grass, smartweed, knotweed, cockle-bur, wildbuckwheat, kochia, medic, corn cockle, ragweed, sowthistle, coffee-weed,croton, cuphea, dodder, fumitory, groundsel, hemp nettle, knowel,spurge, spurry, emex, jungle rice, pondweed, dog fennel, carpetweed,morning glory, bedstraw, ducksalad and naiad; biennials such as wildcarrot, matricaria, wild barley, campion, chamomile, burdock, mullein,roundleaved mallow, bull thistle, hounds-tongue, moth mullein and purplestar thistle; or perennials such as white cockle, perennial rye-grass,quackgrass, Johnson grass, Canada thistle, hedge bindweed, Bennudagrass, sheep sorrel, curly dock, nut-grass, field chickweed, dandelion,campanula, field bindweed, Russian knapweed, mesquite, toadflax, yarrow,aster, gromwell, horsetail, ironweed, sesbania, bulrush, cattail andwinter-cress.

Similarly, such weeds can be classified as broad-leaf or grassy weeds.it is economically desirable to control the growth of such weeds withoutdamaging beneficial plants or livestock.

The new compound of this invention is particularly valuable for weedcontrol because it is toxic to many species and groups of weeds whilerelatively nontoxic to many beneficial plants. The exact amount ofcompound required will depend on a variety of factors, including thehardiness of the particular weed species, weather, type of soil, methodof application, the kind of beneficial plants in the same area, and thelike. Thus, while the application of up to only about one or two ouncesof the active compound per acre may be sufficient for good control of alight infestation of weeds growing under adverse conditions, theapplication of ten pounds or more of active compound per acre may berequired for good control of a dense infestation of hardy perennialweeds growing under favorable conditions.

The herbicidal toxicity of the new compound of this invention can beillustrated by established testing techniques known to the art.

The herbicidal activity of the compound of this invention wasdemonstrated by experiments carried out for the postemergence control ofa variety of weeds. In these experiments the compound2-(2,4-dichlorophenoxyacetyl)-4-methyll,2,4-oxadiazolidine=3,5-dione wasformulated as an aqueous emulsion and sprayed at the indicated dosage onthe foliage of the various weeds that had attained a prescribed size.After spraying the plants were placed in a greenhouse and watered dailyor more frequently. Water was not applied to the foliage of the treatedplants. The severity of the injury was determined ]0 to days aftertreatment and was rated on the scale of from 0 to 10 as follows: 0 noinjury, 1,2 =slight injury, 3,4 moderate injury, 5,6 moderately severeinjury, 7,8,9 severe injury and 10 death. The effectiveness of thesecompounds is demonstrated by the following data:

-do- 4 10 -do- 2 l0 Crabgrass 8 9 -do- 4 9 -do- 2 8 Curly Dock 8 10 -do-4 to -do- 2 9 Foxtail 8 l0 -do- 4 10 -do- 2 9 Mustard Weed 8 10 -do- 410 -do- 2 l0 Pigweed 8 10 -do- 4 10 -do- 2 8 Velvet Leaf 8 l0 -do- 4 l0-du- 2 I0 I claim:

1. A compound selected from the group consisting of potassium4-methyl-l,2,4-oxadiazolidine-3,S-dione and sodium 4- methyl- 1,2,4-oxadiazolidine-3,5-dione.

2. The compound of claim 1, potassium4-methyl-l,2,4-oxadiazolidine-3,5-dione.

3. The compound of claim 1, sodium4-methyl-l,2.4-oxadiazolidine-3,5-dione.

2. The compound of claim 1, potassium 4-methyl-1,2,4-oxadiazolidine-3,5-dione.
 3. The compound of claim 1, sodium 4-methyl-1,2,4-oxadiazolidine-3,5-dione. 